Crop and pest protection agents have conventionally been formulated in solid or liquid compositions, usually in the form of a concentrate for ease of handling and transportation. The concentrate is generally diluted with water by the user before application. Many liquid formulations in the form of emulsifiable or near-emulsifiable concentrates may contain a very high proportion of organic solvents (often up to 80 percent), which are increasingly coming under scrutiny for their potential negative effect on the environment.
Water-based suspension concentrates, which are another conventionally available form, are often viscous giving rise to handling problems and loss of active ingredient through retention in the packaging. Solid formulations, which may also be commercially available, can also have disadvantages; the more common granules and powders in particular can be difficult to measure but more importantly can be dusty and pose inhalation hazards for the formulator and the user. Tablets have not been used extensively because they are often slow to dissolve. In addition, solid formulations have been found generally to possess a lower biological activity than liquid formulations. Also, with unsophisticated mixing techniques at the site of use, the tendency of solid forms not to disperse immediately can cause not only clogging of spray equipment with undispersed formulation, but also an inadequate application of active ingredient to the crop or area to be treated.
Based on the foregoing, there is a need for fast-dispersing, solid pesticide formulations which have improved handling characteristics and enhanced biological activity over conventional forms, to satisfy both environmental concerns and provide an effective pesticidal product with commercially acceptable levels of stability for long term use.